This invention relates to a novel apparatus for forming emulsions of oil in water and, in particular, for processing various water-oil mixtures into emulsions of desired characteristics, for example, optimum water-droplet size within the oil matrix of the emulsion.
The use of water-in-oil emulsions is well known in the art of combustion. Not only can small quantities of water act as a catalyst in combustion of hydrocarbon fuels, but the water can allow attainment of higher operating temperatures, cleaner heat-transfer surfaces and the resulting efficiencies of combustion attributable to such benefits. As a consequence, a great deal of work has gone into providing means and processes for making and using water oil emulsions. Among some of the patents relating to this art are:
U.S. Pat. Nos. 4,008,038; 4,116,160 and 4,144,015 to Berthiaume discuss some emulsification systems related to the augmentation of emulsions with gases tending to expand to form microdroplets for combustion. U.S. Pat. No. 4,479,805 to Batra describes the use of similar equipment to diminish the size of asphaltene "particles" in fuel with the aid of the presence of water. Other inventions related to formation of such emulsions include U.S. Pat. No. 4,081,863 to Rees describing a high-pressure emulsifier. Other patents relating to water in combustion fuel are U.S. Pat. Nos. 3,938,933 to Armas; 3,862,819 to Wentworth; 3,814,567; 3,979,992; 3,741,712; and 3,766,942 to Delatronchette; 3,527,581 to Brownwell; 3,606,868 to Voogd; and 2,104,311 to Russell.
Among publications relating to emulsion of oil in water are "Emulsions as Fuels" Mechanical Engineering, November 1976, Pages 36-41 and "The Effect of Water/Residual Oil Emulsions on Air Pollutant Emissions & Efficiency of Commercial Boiler" ASME Paper No. 75-WA/APC-1 delivered at the 1975 Winter Annual Meeting of the American Society of Mechanical Engineers, Nov. 30, to Dec. 4, 1975 in Houston, Tex.
Flocculation of oil has been reported upon in an article by Suzuki, A. et al in J. Colloid & Int. Science, 29 (3) 552, 1969, and in an article by Fogler et al: "Physical Properties and Stability of Water in Fuel Oil Emulsions; DOT/RSPA/DPB 50/79/16.
Other publications have taught the importance of water-droplet size in fuel systems indicating that the sizes could be too small as well as too large.
In spite of the large amount of attention given to the subject, it still has been a problem to provide an apparatus which would allow one to obtain the optimum emulsion for a given water-oil system even though the properties of oil to be emulsified and even the amount of water to be used in forming the emulsification vary substantially from time to time.